The invention relates to surgical apparatus for retracting the sternum and more particularly relates to retraction apparatus which exposes the Internal Mammary Artery (IMA) during coronary bypass surgery.
In surgical operations involving the chest cavity, a retraction apparatus is needed to retract bone structures to provide exposure to the operative site. Coronary bypass procedures necessitate retraction apparatus for exposing the Internal Mammary Artery which runs along the underside of the rib cage. The retraction apparatus must elevate one side of the rib cage while avoiding the application of downward pressure on the other side. Pressure applied to the sternum during surgery can cause trauma.
Heretofore, retraction devices performing sternal separation were tilted to expose the IMA, but such structure applied downward pressure on the non-elevated side of the rib cage. As mentioned above, such pressure can cause trauma in the patient.
To overcome the problem of downward pressure, retraction devices have been developed such as that disclosed in U.S. Pat. No. 3,572,326. However, such devices comprise a large number of components which make its assembly very difficult and time consuming. In many cases, such devices obstruct exposure of the IMA rather than facilitating it.
In order to simplify the set-up procedure, a table mounted retractor has been developed which comprises few components. However, such devices do not perform sternal spreading and thus the use of a separate sternal spreader to expose the heart for bypass preparation is required. The presence of a second device introduces a higher probability of non-sterility in the operating environment. Moreover, in operations requiring bilateral exposure of both IMAs, such retractors must be moved from one side of the surgical table to the other. Because the rail clamp which secures the retractor to the surgical table rail is disposed below the field of sterilization, any re-locating of the device presents sterility problems. In addition, moving the retractor wastes valuable time during surgery.
It is therefore an object of the present invention to provide an improved IMA retractor.
It is another object of the invention to provide a table mounted sternal retractor which eliminates downward pressure on the patient and facilitates quick and easy set-up.
It is a further object of the invention to provide a sternal retractor which reduces the possibility of contamination by eliminating relocation of the apparatus during bypass operations requiring bilateral exposure of the IMAs.